Hydroquinidine Cuts Serious Arrhythmic Events in SQTS

Last Updated: December 13, 2017.
Treatment with hydroquinidine prolongs the QT interval in patients with short QT syndrome and reduces the occurrence of life-threatening arrhythmic events, according to a study published in the Dec. 19 issue of the Journal of the American College of Cardiology.

Patients on HQ had lower rate of life-threatening arrhythmic events, number of LAE per patient

WEDNESDAY, Dec. 13, 2017 (HealthDay News) -- Treatment with hydroquinidine (HQ) prolongs the QT interval in patients with short QT syndrome (SQTS) and reduces the occurrence of life-threatening arrhythmic events (LAE), according to a study published in the Dec. 19 issue of the Journal of the American College of Cardiology.

In a cohort study, Andrea Mazzanti, M.D., from the IRCCS ICS Maugeri in Pavia, Italy, and colleagues conducted a matched-period analysis for the occurrence of LAE in 17 SQTS patients who received long-term HQ and compared the annual incidence of LAE off- and on-HQ in 16 SQTS patients who survived cardiac arrest.

The researchers found that 15 of the 17 patients receiving HQ therapy continued treatment for six ± one years. In all patients, QTc prolongation was observed (by 60 ± 6 ms; P < 0.001). In comparison of LAE for the six years before and after HQ, patients on HQ experienced a reduction in the rate of LAE (40 to 0 percent; P = 0.03) and the number of LAE per patient (0.73 ± 0.3 to 0; P = 0.026). In the 16 patients with a previous cardiac arrest, the annual rate of LAE decreased from 12 percent before HQ to 0 percenton therapy (P = 0.028).

"We demonstrated for the first time that treatment with HQ was associated with a lower incidence of LAE in SQTS patients. These data point to the importance that quinidine, that in several countries has been removed from the market, remains available worldwide for patients with SQTS," the authors write. "In the present study, therapy with HQ has been proven to be safe, with a relatively low rate of side effects."